Venous Sampling

Venous sampling is a diagnostic procedure that uses imaging guidance to insert a catheter into a specific vein and remove blood samples for laboratory analysis. Abnormal levels of certain substances in the blood may indicate the presence of disease in the organ or tissue that produces them.

When is this procedure recommended?

The procedure is commonly done for patients with a particular form of high blood pressure called primary aldosteronism to guide treatment between surgery and medical therapy. It is less commonly done for patients with Cushing syndrome, an endocrine disorder in which high levels of cortisol may be found in the blood.

How is this procedure performed?

A small catheter is inserted into a vein in the groin or neck under local anesthesia and using real-time radiologic guidance, a catheter is positioned into the necessary veins. A small amount of blood is then sampled from these veins which drain the specific organ in question (e.g., kidneys, adrenal glands and pancreas). This procedure is typically performed on an outpatient basis and the recovery time can be as short as a few hours.

Before venous sampling begins, iodinated contrast material is injected to map the veins and locate the vein or veins of interest.  Once the vein is located, the catheter is advanced to the target area under fluoroscopic guidance. A syringe is then used to withdraw a blood sample. In some cases, two catheters are inserted in order to compare hormone levels between paired glands. Additional blood samples may be taken after administration of medication that increases the hormone production of the adrenal glands. The samples are then sent to a laboratory for analysis of compounds released by the organs or tissue.

What are the benefits?

Venous sampling provides important information about organ and gland function that cannot always be determined by imaging, such as:

  • Presence of disease in one or more glands
  • Potential sources of high blood pressure
  • The location of glands that can be difficult to find with imaging
  • Whether or not surgery is needed


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